Meta-cognition about biological sex and gender-stereotypic physical appearance: Consequences for the assessment of leadership competence

Previous findings are inconsistent with regard to whether men are judged as being more or less competent leaders than women. However, masculine-relative to feminine-looking persons seem to be judged consistently as more competent leaders. Can this different impact of biological sex and physical appearance be due to the disparate availability of meta-cognitive knowledge about both sources? The results of Study 1 indicated that individuals possess meta-cognitive knowledge about a possible biasing influence of persons’ biological sex, but not for their physical appearance. In Study 2, participants judged the leadership competence of a male versus female stimulus person with either masculine or feminine physical appearance. In addition, the available cognitive capacity was manipulated. When high capacity was available, participants corrected for the influence of stimulus persons’ sex, but they fell prey to this influence under cognitive load. However, the effect of physical appearance was not moderated by cognitive capacity.

Osteogenic differentiation of bone marrow stromal cells is hindered by the presence of intervertebral disc cells.

BACKGROUND Clinical observations indicate that the presence of nucleus pulposus (NP) tissue during spinal fusion hinders the rate of disc ossification. While the underlying mechanism remains unknown, this observation could be due to incomplete removal of NP cells (NPCs) that secrete factors preventing disc calcification, such as bone morphogenetic protein (BMP) antagonists including noggin and members of the DAN (differential screening selected gene aberrative in neuroblastoma) family. METHODS Monolayer human bone marrow-derived mesenchymal stem cells (MSCs) were cocultured withNPCs and annulus fibrosus cells (AFCs) embedded in alginate for 21 days. At the end of coculture, MSCs were stained for mineral deposition by alizarin red, and relative expression of bone-related genes [Runt-related transcription factor 2, (RUNX2), Osteopontin (OPN), and Alkaline phosphatase (ALP)] and ALP activity were analyzed. Relative expression of three BMP antagonists, chordin (CHRD), gremlin (GREM1), and noggin (NOG), was determined in primary human NPCs and AFCs. These cells were also stained for Gremlin and Noggin by immunocytochemistry. RESULTS Alizarin red staining showed that MSC osteogenesis in monolayer cultures was inhibited by coculture with NPCs or AFCs. ALP activity and RT-PCR analyses confirmed these results and demonstrated inhibition of osteogenesis of MSC in the presence of disc cells. NOG was significantly up-regulated in MSCs after coculture. Relative gene expression of intervertebral disc (IVD) cells showed higher expression of GREM1 in NPCs than in AFCs. CONCLUSIONS We show that primary IVD cells inhibit osteogenesis of MSCs. BMP inhibitors NOG, GREM1 and CHRD were expressed in IVD cells. GREM1 appears to be differentially expressed in NPCs and AFCs. Our results have implications for the design and development of treatments for non-union in spinal fusion.

The Effects of Trade Orientation and Human Capital on Total Factor Productivity

We study the effects of trade orientation and human capital on total factor productivity for a pooled cross-section, time-series sample of developed and developing countries. We first estimate total factor productivity from a parsimonious specification of the aggregate production function involving output per worker, capital per worker, and the labor force, both with and without the stock of human capital. Then we consider a number of potential determinants of total factor productivity growth including several measures of trade orientation as well as a measure of human capital. We find that a high degree of openness benefits total factor productivity and that human capital contributes to total factor productivity only after our measure of openness passes some threshold level. Before that threshold, increases in human capital actually depress total factor productivity. Finally, we also consider the issue of convergence of real GDP per worker and total factor productivity, finding more evidence of convergence for the latter than for the former.

Perceived gender relations and sexual relations among undergraduate female students in the Mekong Delta of Vietnam

Background. Literature worldwide has documented associations between gender-based relationship inequity, sexual communication self-efficacy, and actual use of condoms and contraceptives among young women. However studies that have rigorously tested these associations in southern Vietnam are extremely rare. This study aimed to examine these associations and other current sexual practices among undergraduate female students in the Mekong Delta. Method. A qualitative study was conducted to examine the operationalization of the Theory of Gender and Power and to obtain salient and culture-relevant dimensions of perceived gender relations in the Mekong Delta of Vietnam. Sixty-four undergraduate female students from two universities participated in eight group discussions focusing on their viewpoints regarding national and local gender equity issues. A subsequent cross-sectional survey consisting of 1181 third-year female students from Can Tho University and An Giang University was conducted. Latent variable modeling and logistic regression were employed to examine the hypothesized associations. Results. Dimensions of perceived gender relations were attributable to theoretical structures of labor, power, and cathexis. Perceptions about gender inequities were comparable to findings from several reports, in which women were still viewed as inferior and subordinate to men. Among students who had ever had a boyfriend(s) (72.4%), 44.8% indicated that their boyfriend had ever asked for sex, 13% had ever had penile-vaginal sex, and 10.3% had ever had oral sex. For those who had ever had penile-vaginal sex, 33% did not use any contraceptive method at first sex. The greater a student’s perception that women were subordinate to men, the lower her self-efficacy for sexual communication and the lower her actual frequencies of asking for contraceptive or condom use. Sexual communication self-efficacy was marginally associated with actual contraceptive use (p=.039) and condom use (p=.092) at first sex. Conclusion. Sexual health promotion strategies should address the influence of perceived unequal gender relations on young women’s sexual communication self-efficacy and the subsequent impact on actual contraceptive and condom use.^

Longitudinal and logistic analysis of endocrine hormone profiles, physical maturation, and candidate genes related to pubertal events in children

Children who experience early pubertal development have an increased risk of developing cancer (breast, ovarian, and testicular), osteoporosis, insulin resistance, and obesity as adults. Early pubertal development has been associated with depression, aggressiveness, and increased sexual prowess. Possible explanations for the decline in age of pubertal onset include genetics, exposure to environmental toxins, better nutrition, and a reduction in childhood infections. In this study we (1) evaluated the association between 415 single nucleotide polymorphisms (SNPs) from hormonal pathways and early puberty, defined as menarche prior to age 12 in females and Tanner Stage 2 development prior to age 11 in males, and (2) measured endocrine hormone trajectories (estradiol, testosterone, and DHEAS) in relation to age, race, and Tanner Stage in a cohort of children from Project HeartBeat! At the end of the 4-year study, 193 females had onset of menarche and 121 males had pubertal staging at age 11. African American females had a younger mean age at menarche than Non-Hispanic White females. African American females and males had a lower mean age at each pubertal stage (1-5) than Non-Hispanic White females and males. African American females had higher mean BMI measures at each pubertal stage than Non-Hispanic White females. Of the 415 SNPs evaluated in females, 22 SNPs were associated with early menarche, when adjusted for race ( p<0.05), but none remained significant after adjusting for multiple testing by False Discovery Rate (p<0.00017). In males, 17 SNPs were associated with early pubertal development when adjusted for race (p<0.05), but none remained significant when adjusted for multiple testing (p<0.00017). ^ There were 4955 hormone measurements taken during the 4-year study period from 632 African American and Non-Hispanic White males and females. On average, African American females started and ended the pubertal process at a younger age than Non-Hispanic White females. The mean age of Tanner Stage 2 breast development in African American and Non-Hispanic White females was 9.7 (S.D.=0.8) and 10.2 (S.D.=1.1) years, respectively. There was a significant difference by race in mean age for each pubertal stage, except Tanner Stage 1 for pubic hair development. Both Estradiol and DHEAS levels in females varied significantly with age, but not by race. Estradiol and DHEAS levels increased from Tanner Stage 1 to Tanner Stage 5.^ African American males had a lower mean age at each Tanner Stage of development than Non-Hispanic White males. The mean age of Tanner Stage 2 genital development in African American and Non-Hispanic White males was 10.5 (S.D.=1.1) and 10.8 (S.D.=1.1) years, respectively, but this difference was not significant (p=0.11). Testosterone levels varied significantly with age and race. Non-Hispanic White males had higher levels of testosterone than African American males from Tanner Stage 1-4. Testosterone levels increased for both races from Tanner Stage 1 to Tanner Stage 5. Testosterone levels had the steepest increase from ages 11-15 for both races. DHEAS levels in males varied significantly with age, but not by race. DHEAS levels had the steepest increase from ages 14-17. ^ In conclusion, African American males and females experience pubertal onset at a younger age than Non-Hispanic White males and females, but in this study, we could not find a specific gene that explained the observed variation in age of pubertal onset. Future studies with larger study populations may provide a better understanding of the contribution of genes in early pubertal onset.^

IDENTIFYING GENETIC VARIANTS AND CHARACTERIZING THEIR ROLE IN CLUBFOOT

Clubfoot is a common, complex birth defect affecting 4,000 newborns in the United States and 135,000 world-wide each year. The clubfoot deformity is characterized by inward and rigid downward displacement of one or both feet, along with persistent calf muscle hypoplasia. Despite strong evidence for a genetic liability, there is a limited understanding of the genetic and environmental factors contributing to the etiology of clubfoot. The studies described in this dissertation were performed to identify variants and/or genes associated with clubfoot. Genome-wide linkage scan performed on ten multiplex clubfoot families identified seven new chromosomal regions that provide new areas to search for clubfoot genes. Troponin C (TNNC2) the strongest candidate gene, located in 20q12-q13.11, is involved in muscle contraction. Exon sequencing of TNNC2 did not identify any novel coding variants. Interrogation of fifteen muscle contraction genes found strong associations with SNPs located in potential regulatory regions of TPM1 (rs4075583 and rs3805965), TPM2 (rs2025126 and rs2145925) and TNNC2 (rs383112 and rs437122). In previous studies, a strong association was found with rs3801776 located in the basal promoter of HOXA9, a gene also involved in muscle development and patterning. Altogether, this data suggests that SNPs located in potential regulatory regions of genes involved in muscle development and function could alter transcription factor binding leading to changes in gene expression. Functional analysis of 3801776/HOXA9, rs2025126/TPM2 and rs2145925/TPM2 showed altered protein binding, which significantly influenced promoter activity. Although the ancestral allele (G) of rs4075583/TPM1 creates a DNA-protein complex, it did not affect TPM1 promoter activity. However and importantly, in the context of a haplotype, rs4075583/G significantly decreased TPM1 promoter activity. These results suggest dysregulation of multiple skeletal muscle genes, TPM1, TPM2, TNNC2 and HOXA9, working in concert may contribute to clubfoot. However, specific allelic combinations involving these four regulatory SNPs did not confer a significantly higher risk for clubfoot. Other combinations of these variants are being evaluated. Moreover, these variants may interact with yet to be discovered variants in other genes to confer a higher clubfoot risk. Collectively, we show novel evidence for the role of skeletal muscle genes in clubfoot indicating that there are multiple genetic factors contributing to this complex birth defect.

Transcriptional regulation of cell lineage-specific expression of the murine type I collagen genes and of osteoblast differentiation

The aim of my project is to examine the mechanisms of cell lineage-specific transcriptional regulation of the two type I collagen genes by characterizing critical cis-acting elements and trans-acting factors. I hypothesize that the transcription factors that are involved in the cell lineage-specific expression of these genes may have a larger essential role in cell lineage commitment and differentiation. I first examined the proximal promoters of the proα1(I) and the proα2(I) collagen genes for cell type-specific DNA-protein interactions, using in vitro DNaseI and in vivo DMS footprinting. These experiments demonstrated that the cis-acting elements in these promoters are accessible to ubiquitous DNA-binding proteins in fibroblasts that express these genes, but not in other cells that do not express these genes. I speculate that in type I collagen-expressing cells, cell type-specific enhancer elements facilitate binding of ubiquitous proteins to the proximal promoters of these genes. Subsequently, examination of the upstream promoter of the proα(I) collagen gene by transgenic mice experiments delineated a 117 bp sequence (-1656 to -1540 bp) as the minimum element required for osteoblast-specific expression. This 117 bp element contained two segments that appeared to have different functions: (1) the A-segment, which was necessary to obtain osteoblast-specific expression and (2) the C-segment, which was dispensable for osteoblast-specific expression, but was necessary to obtain high-level expression. In experiments to identify trans-acting factors that bind to the 117 bp element, I have demonstrated that the cell lineage-restricted homeodomain proteins, Dlx2, Dlx5 and mHOX, bound to the A-segment and that the ubiquitous transcription factor, Sp1, bound to the C-segment of this element. These results suggested a model where the binding of cell lineage-restricted proteins to the A-segment and of ubiquitous proteins to the C-segment of the 117 bp element of the proα1 (I) collagen gene activated this gene in osteoblasts. These results, combined with additional evidence that Dlx2, Dlx5 and mHOX are probably involved in osteoblast differentiation, support my hypothesis that the transcription factors involved in osteoblast-specific expression of type I collagen genes may have essential role in osteoblast lineage commitment and differentiation. ^

Abundance, Electron transport System (ETS) activity and respiration rates of pelagic decapods from the Benguela upwelling system during AFR258, D356 and MSM17/3

Decapods were sampled with a 1 m**2 MOCNESS (mainly upper 1000 m) in the northern Benguela Current during three cruises in December 2009, September/October 2010 and February 2011. Although pelagic decapods are abundant members of the micronekton community, information about their ecophysiology is very limited. Species-specific regional distribution limits were detected for various decapod species (e.g. Plesionika carinata, Sergestes arcticus, Pasiphaea semispinosa). Significant diel vertical migration patterns were determined for three caridean and three penaeiodean species. Biomass was variable and ranged from 23 to 2770 mg dry mass m**-2 with highest values for P. semispinosa. Fatty acid and stable isotope analyses revealed that the examined decapod species are omnivorous tocarnivorous except for the herbivorous to omnivorous species P. carinata. Calanid copepods such as Calanoides carinatus were identified as an important prey item especially for caridean species. Community consumption rates of pelagic decapods derived from respiration rates ranged from 7 mg C m**-2 d**-1 (231S) to 420 mg C m**-2 d**-1 (191S, 171S). A potential active respiratory carbon flux was calculated for migrating pelagic decapods with 4.4 mg C m**- d**-1 for the upper 200 m and with 2.6 mg C m**-2 d**-1 from the base of the euphotic zone to a depth of 600 m. Overall, pelagic decapods apparently play a more prominent role in the northern Benguela Current ecosystem than previously assumed and may exert a substantial predation impact on calanid copepods (up to 13% d**-1 of standing stock).

Environmental magnetism, geochemical measurements and colour reflectance of two sediment cores: GeoB4905-4 off Cameroon and GeoB4906-3 off Gabon

We combine environmental magnetism, geochemical measurements and colour reflectance to study two late Quaternary sediment cores: GeoB 4905-4 at 2° 30 N off Cameroon and GeoB 4906-3 at 0° 44 N off Gabon. This area is suitable for investigating precipitation changes over Central and West Africa because of its potential to record input of aeolian and fluvial sediments. Three magnetozones representing low and high degree of alteration of the primary rock magnetic signals were identified. The magnetic signature is dominated by fine-grained magnetite, while residual haematite prevails in the reduced intervals, showing increase in concentration and fine grain size at wet intervals. Our records also show millennial-scale changes in climate during the last glacial and interglacial cycles. At the northern location, the past 5.5 ka are marked by high-frequency oscillations of Ti and colour reflectance, which suggests aeolian input and hence aridity. The southern location remains under the influence of the Intertropical Convergence Zone and thus did not register aeolian signals. The millennial-scale climatic signals indicate that drier and/or colder conditions persisted during the late Holocene and are synchronous with the 900 a climatic cycles observed in Northern Hemisphere ice core records.

Stable oxygen isotope data of Globorotalia inflata and radiocarbon dates for sediment cores GeoB6211-2, GeoB13862-1, and GeoB6308-3

The Southern Westerly Winds (SWW) exert a crucial influence over the world ocean and climate. Nevertheless, a comprehensive understanding of the Holocene temporal and spatial evolution of the SWW remains a significant challenge due to the sparsity of high-resolution marine archives and appropriate SWW proxies. Here, we present a north-south transect of high-resolution planktonic foraminiferal oxygen isotope records from the western South Atlantic. Our proxy records reveal Holocene migrations of the Brazil- Malvinas Confluence (BMC), a highly sensitive feature for changes in the position and strength of the northern portion of the SWW. Through the tight coupling of the BMC position to the large-scale wind field, the records allow a quantitative reconstruction of Holocene latitudinal displacements of the SWW across the South Atlantic. Our data reveal a gradual poleward movement of the SWW by about 1-1.5° from the early to the mid-Holocene. Afterwards variability in the SWW is dominated by millennial-scale displacements in the order of 1° in latitude with no recognizable longer-term trend. These findings are confronted with results from a state-of-the-art transient Holocene climate simulation using a comprehensive coupled atmosphere-ocean general circulation model. Proxy-inferred and modeled SWW shifts compare qualitatively, but the model underestimates both orbitally forced multi-millennial and internal millennial SWW variability by almost an order of magnitude. The underestimated natural variability implies a substantial uncertainty in model projections of future SWW shifts.

Raw grain-size distributions of the sediment trap time series CB 14 upper, CB 15 lower, CB 16 lower, CBi 1 upper, CBi 2 upper and CBi 3 upper

in preparation